1. Field
Subject matter disclosed herein relates to techniques to determine a metric quantifying a glycemic health of a patient.
2. Information
The pancreas of a normal healthy person produces and releases insulin into the blood stream in response to elevated blood plasma glucose levels. Beta cells (β-cells), which reside in the pancreas, produce and secrete insulin into the blood stream as it is needed. If β-cells become incapacitated or die, which is a condition known as Type 1 diabetes mellitus (or in some cases, if β-cells produce insufficient quantities of insulin, a condition known as Type 2 diabetes), then insulin may be provided to a body from another source to maintain life or health.
Traditionally, because insulin cannot be taken orally, insulin has been injected with a syringe. More recently, the use of infusion pump therapy has been increasing in a number of medical situations, including for delivering insulin to diabetic individuals. For example, external infusion pumps may be worn on a belt, in a pocket, or the like, and they can deliver insulin into a body via an infusion tube with a percutaneous needle or a cannula placed in subcutaneous tissue.
To determine an appropriate therapy for treating a patient's diabetic conditions, a blood glucose concentration is typically measured using one or more techniques such as, for example, metered blood glucose measurements (e.g. using finger sticks) or continuous glucose monitoring from processing signals generated by a blood glucose sensor inserted into subcutaneous tissue. While contemporaneous observations of blood glucose concentration may be an effective metric for determining an appropriate therapy for addressing an immediate condition (e.g., determining a size of an insulin bolus to be given to a patient), contemporaneous observations of blood glucose alone do not necessarily provide an indication of a patient's glycemic health over a time period, for example. Other metrics for assessing a patients' overall glycemic health may include a measurement of hemoglobin A1c (or HbA1c), which is one form of glycohemoglobin. Here, such a hemoglobin is irreversibly glycated at one or both N-terminal valine residues of a β-chain of hemoglobin A0. Glycation of hemoglobin in a patient is typically quantified as a percentage of total hemoglobin.
A strong relationship exists between hemoglobin A1c levels in a diabetes patient and risks of micro-vascular complications. Accordingly, hemoglobin A1c measurements have become an integral component of the treatment of diabetes patients.